Humbert II, dauphin of Viennois (1333-1349), was leader of a crusade that went to the relief of Smyrna (mod. Izmir, Turkey) in western Anatolia in 1346.
Humbert was the son of John II, dauphin of Viennois, and Beatrix of Hungary. He spent his youth in Hungary and Naples, where he married Marie of Baux in 1332. He became dauphin of Viennois on the death of his elder brother Guiges in 1333.
Ambition and vanity, but also piety, motivated Humbert to take part in a crusade. At the beginning of 1345, like other rulers, Humbert received appeals from Pope Clement VI for a new crusade to aid Smyrna, which had been captured by a Christian naval league in October 1344 from Umur Beg, emir of Aydin. Humbert wanted to lead this expedition, against the misgivings of the pope, the cardinals, and even his own councillors, but Clement VI yielded. On 26 May, in Avignon, Humbert was named captain general of the Holy See against the Turks, took the cross, and received the standard of the church.
Humbert sailed from Marseilles in late August, and proceeded to Venice, collecting Italian crusaders on his way. He left Venice at the beginning of November and sailed to the island of Negroponte (Euboia), situated off eastern Greece. In February or more likely March 1346, the crusaders defeated the Turks on the island of Mytilene. In June they arrived at Smyrna and fortified the town against the castle, which was still occupied by Umur Beg. Skirmishes took place, but more people were killed by disease than by fighting. Humbert left Smyrna for Rhodes (mod. Rodos, Greece). He was so ill that he wrote his will on 29 January 1347, although it was his wife who died several weeks later. On 19 March Clement VI relieved him of his crusade vow and authorized him to return to his lands, giving him permission to trade with the Muslims of Egypt with 2 ships and 12 galleys.
Humbert II’s expedition was a complete failure: he lost his beloved wife, a great deal of money, and most of what little renown he possessed. In 1349 he ceded the Viennois to the king of France and entered the Dominican Order. He became titular Latin patriarch of Alexandria in 1351.